Re: [tlug] Re: [RFC] Outline of the fast HTTP talk (PHP benchmark)

["Stephen J. Turnbull" <turnbull@example.com>]

Curt Sampson writes:

 > According to the schedtool manpage:
 > 
 >     AFFINITY MASK
 >        The affinity-argument determines on which CPUs a process is
 >        allowed to run. It consists of a simple bitmask represented in
 >        hexadecimal.  CPU0 is denoted by the least-significant bit,
 >        CPU1 by the second  least-significant and so on.
 > 
 > In normal MP usage (e.g., according to Pfister's _In Search of
 > Clusters_) the affinity is the CPU on which it would be preferred to
 > give a particular process its next quantum.

If "affinity" is being used as a concrete noun rather than a
relationship, so much the worse for Pfister and his/her followers, who
should take a remedial course in English usage.

That said, I don't see a conflict, except if Pfister is really serious
about "*the* CPU" (ie, the process can have affinity to exactly one
CPU).  Otherwise, I think you're confusing a general definition of the
term with a particular implementation that you like, and are harassing
Linux for having a different implementation.  In particular, Linux
apparently implements "preference" in a particularly simple way:
either a CPU is "preferred" or it is *prohibited*, and all preferred
CPUs have (implicitly) equal affinity for the process.